Elastomeric flexible elements are often used in the oil industry in flexible pipe joints for coupling or supporting segments of a pipeline or riser. A limitation of the elastomeric flexible elements is reduced performance when exposed to heat from fluid flowing in the pipeline or riser, and to chemicals in the fluid. A conventional way of dealing with this limitation is by using a two-stage bellows.
For example, as described in Whightsil, Sr. et al. U.S. Pat. No. 5,133,578, a flexible joint is employed to sealingly connect a pair of tubular members while still permitting limited articulated movement there between. The flexible joint includes a housing with upper and lower ring-like plates coaxially arranged about the tubular members. A pair of annular elastomeric bearings is positioned within the housing and acts against shoulders of the tubular members to flexibly retain the tubular members within the housing. A bellows sealingly couples the tubular members together while permitting movement there between. An annular chamber formed between the bellows and housing is filled with a fluid, such as silicon or oil. Means is provided for adjusting the volume of the chamber or volume of fluid in the chamber to maintain an approximately zero pressure differential across the bellows.
Additional ways of limiting exposure of the elastomeric flexible element to the heat of fluid flowing in a pipeline or riser are described in Moses et al. U.S. Pat. No. 7,341,283 issued Mar. 11, 2008. The flexible joint includes a heat shield of low heat conductivity material integrated into the inner profile of the pipe extension and interposed between the central bore of the pipe joint and the flexible element, low heat conductivity metal alloy components between the hot production fluid and the flexible element, high temperature resistant elastomer at least in the warmest inner elastomer layer of the flexible element, and a flexible element constructed to shift strain from the warmer inner elastomer layers to the colder outer elastomer layers by providing greater shear area, different layer thickness, and/or higher elastic modulus elastomer for the warmer inner elastomer layers.